Definition from http://dictionary.reference.com:
noun--a feeling of deep sympathy and sorrow for another who is stricken by misfortune, accompanied by a strong desire to alleviate the suffering.
Compassion is a key ingredient of being a great teacher. This is because if you show compassion to a person they will try their hardest to make you happy because they know you care for them. Although too much compassion may be a negative thing in the classroom. If a teacher has too much compassion for certain students it teaches those students that they are above the rules and also they can take advantage of your kindness. But if a teacher has no compassion in the classroom the kids may think that no matter how hard they try they will never get it right; so they stop trying to impress you. So although compassion is a great thing to have as a teacher, you have to know how to equal it out so there is not too little or too much.
A time that I remember teachers showing me compassion was in my junior year of high school. It was just after I lost a close family member and was dealing with everything that my teachers showed compassion by helping after school with the homework since I was having troubles concentrating in class and at home. It was only after a couple of weeks that I started doing homework on my own and got on with the normal routine of everything. But there was still this one teacher who was showing me compassion, a little too much now that I look back at it. If I had not done my homework assignment this teacher would excuse it so that I wouldn't have to worry about it. At the time I thought this was very nice, but then I started taking advantage of the situation. At the end of the course I realized that both of us, mostlty myself, had messed up my ablility to learn the material for the course.
This is why I think compassion can be a good and bad characteristic in the classroom. Which is why teachers should use it wisely.
Video about Compassion in the Classroom:
http://www.youtube.com/watch?v=VYY6-EdTzXw